Boris Johnson has accused France of a “naked attempt to steal London’s
financial crown” ahead of a battle between the European Union’s finance
ministers over new powers for a Frankfurt banking supervisor.

The mayor of London launched his attack after Christian Noyer, the governor of the Bank of FrancePhoto: Geoff Pugh

The mayor of London launched his attack after Christian Noyer, the governor of the Bank of France, urged the eurozone this weekend to seek “control” of financial transactions in the single currency that are centred in London.

The row broke out ahead of a meeting in Brussels on Tuesday, where EU ministers will attempt to agree proposals for a “banking union” giving the European Central Bank sweeping supervisory powers over the eurozone’s banks.

“This is a desperate French attack in an effort to make something out of the eurozone crisis,” Mr Johnson said.

“It’s nothing more than a naked attempt to steal London’s financial crown. It shows utter contempt for the principles of the single market and it will not succeed.”

George Osborne will also criticise Mr Noyer at the meeting in Brussels and use the French banker’s threat as a stark example of why Britain wants safeguards to protect it from eurozone protectionism.

More than 40pc of euro-denominated foreign-exchange transactions are conducted in London, a bigger share than the rest of the eurozone combined.

Speaking in Tokyo on Monday Mr Noyer continued to insist that the City of London must be displaced as Europe’s financial centre because Britain would not be included in the costs and obligations involved in a new ECB supervisory regime to regulate the euro’s financial and banking sector.

“It is clear there is no rationale for the biggest financial centre active in our currency or providing services in our economic union being an offshore centre,” he said.

Vince Cable, the Business Secretary, also warned France against using the eurozone banking and debt crisis as a pretext for breaking up the EU’s single market.

“Intelligent French decision makers fully understand that Britain has much to contribute and a crude nationalistic attack on the UK would be counter-productive,” he said.